($rv, $user, $pass) = logon(User Logon, BTN_OK | BTN_CANCEL,
20, qw(white red yellow));
This function displays an input dialog with the specified title, buttons, and
text fields. The following constants are defined for specifying buttons,
and can be ored to provide multiple choices:
The remaining arguments is the max string length and the desired colours
(foreground, background, and caption colour).
The return value of the dialog will be the index value of the chosen button,
as one would normally recieve from the Curses::Widgets::ButtonSet widget, and
the string value of the TextField widgets.